• 한국연소학회지
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• 제9권1호
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• pp.11-17
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• 2004

The purposes of this study are to analyze nitrogen oxides(NOx) formation mechanism and to reduce abnormal NOx emissions in gas turbines. Industrial gas turbines emissions have potential to negative affect to the atmosphere in many different ways such as photochemical smog, acid rain and global warming. In conventional gas turbine combustors, one of the main pollutants such as nitrogen oxide(NOx) species, are principally formed from combustion process of fuel with oxygen in the primary combustion zone, and their emission levels are highly depend on peak temperatures in the combustor. In order to examine the characteristics and the effect of NOx formation, we used gas turbine of which commercial operating in Korea. From the examination, it has been found that NOx emissions are relatively high at low load(output) and during combustion mode change. Also, the effect of Air/Fuel ratio was considered. As the Air/Fuel ratio was increased in Lean-Lean mode, the NOx emission was decreased. The results of this study indicated that NOx emission levels are highly depend on peak temperature and pressure of combustion process in the combustor.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.171-178
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• 2006

The performance in the practical combustion system including reciprocating engines and gas turbine combustors is being much governed by turbulent reacting flow that is often analyzed by both a laminar flamelets concept and flame interaction. The characteristics of laminar flame interaction have been investigated numerically to provide basic understanding of wrinkled turbulent flames under concentration interaction resulting from inhomogeneity in fuel-air mixing, especially focused on the transition of flame characteristics such as diffusion flame, partially premixed diffusion flame, and triple-layer flame by the variation in the degree of premixedness. The extinction stretch rates to the premixedness have also been obtained in this paper. The boundary defining the regime of the existence of triple-layer flames as functions of both stretch rate and premixedness has been determined which agrees well with previously reported experiment measuring OH radical concentration peaks based on PLIF.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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• pp.307-313
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• 2002

In the paper, the prototype development of a 75kW class microturbine for the distributed generation market is partly presented which has continued with the government funding. In the introduction, an overview of the development of microturbines in the world is presented. A series of development procedures are shown with design, manufacture and self-sustaining tests. During the first year, aerodynamic and structural design/analysis, mechanical design are performed for the compressor, the turbine and the combustor. A premixed lean burn combustor technology is used fur the low emission requirements. Foil air bearings and high-speed motors are employed for higher reliability. The self-sustaining conditions have been successfully achieved with the prototype manufactured engine as a preceding operation.

• Journal of Advanced Marine Engineering and Technology
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• 제38권6호
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• pp.658-665
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• 2014

선박용 디젤엔진에서 천연가스의 사용기술은 NOx, SOx 및 GHG의 배출을 단독으로 크게 삭감할 수 있는 기술이다. 특히 셰일가스의 등장으로 가스의 공급이 확대될 것으로 예상되는 가운데 추진기관용 2행정기관에의 이용이 적극적으로 개발 검토되고 있다. 가스엔진의 출력성능은 디젤기관과 비교하여 큰 차이를 보이지 않았으며 연료소비율은 약간 개선되는 것으로 보고되고 있다. 그러나 배기특성에 있어서는 연소기술에 따라서 다른 성능을 나타내고 있으며 희박연소기술에 의하여 NOx 배출량은 85%정도의 감축이 가능한 것으로 알려져 있다. 본 연구에서는 가스엔진의 연소생성물의 발생량을 시뮬레이션 할 수 있는 프로그램을 개발하였다. 개발된 프로그램은 희박연소의 영향은 물론 예혼합연소와 확산연소에 의한 영향도 시뮬레이션 할 수 있는 기능을 가지고 있다. 이를 위해서 실린더 내 상태변화는 2영역모델(Two-zone model)을 이용하고 열발생율 패턴은 Wiebe 함수를 이용하며, 공연비를 입력데이터로 하여 다양한 연소조건에서의 배기생성물의 발생량 예측을 가능하게 하였다.

• 한국수소및신에너지학회논문집
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• 제27권4호
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• pp.357-364
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• 2016

Recently, the world faces the environmental problem such as air pollution due to harmful gas discharged from car and abnormal climate due to the green-house gases increased by the discharge of $CO_2$. Compressed Natural Gas (CNG), one of alternative for this problem, is less harmful, compared to the existing fossil fuel, as gaseous fuel, and less carbon in fuel ingredients and carbon dioxide generation rate relatively favorable more than the existing fuel. However, CNG fuel has the weakness of slow flame propagation speed and difficult fast burn. On the other hand, hydrogen does not include carbon in fuel ingredients, and does not discharge harmful gas such as CO and HC. Moreover, it has strength of quick burning velocity and ignition is possible with small ignition energy source and it's has wide Lean Flammability Limit. If using this hydrogen with CNG fuel, the characteristics of output and discharge gas is improved by the mixer's burning velocity improved, and, at the same time, is possible to have stable lean combustion with the reduction of $CO_2$ expected. Therefore, this research tries to identify the characteristics of engine and emission gas when mixing CNG fuel and hydrogen in each portion and burning them in spark igniting engine, and grasp the combustion stability and emission gas characteristics according and use it as the basic data of hydrogen-CNG premixed engine.